Project description:ABSTRACT Background: Viral myocarditis is a life-threatening illness that may lead to heart failure or cardiac arrhythmias. This study examined whether human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) could be used to model the pathogenic processes of coxsackievirus-induced viral myocarditis and to screen antiviral therapeutics for efficacy. Methods and Results: Human iPSC-CMs were infected with a luciferase-expressing mutant of the coxsackievirus B3 strain (CVB3-Luc). Brightfield microscopy, immunofluorescence, and calcium imaging were used to characterize virally infected hiPSC-CMs. Viral proliferation on hiPSC-CMs was subsequently quantified using bioluminescence imaging. For drug screening, select antiviral compounds including interferon beta 1 (IFNβ1), ribavirin, pyrrolidine dithiocarbamate (PDTC), and fluoxetine were tested for their capacity to abrogate CVB3-Luc proliferation in hiPSC-CMs in vitro. The ability of some of these compounds to reduce CVB3-Luc proliferation in hiPSC-CMs was consistent with the reported drug effects in previous studies. Finally, mechanistic analyses via gene expression profiling of hiPSC-CMs infected with CVB3-Luc revealed an activation of viral RNA and protein clearance pathways within these hiPSC-CMs after IFNβ1 treatment. Conclusions: This study demonstrates that hiPSC-CMs express the coxsackievirus and adenovirus receptor, are susceptible to coxsackievirus infection, and can be used to confirm antiviral drug efficacy. Our results suggest that the hiPSC-CM/CVB3-Luc assay is a sensitive platform that could be used to screen novel antiviral therapeutics for their effectiveness in a high-throughput fashion. For this experiment, human induced pluripotent stem cell derived cardiomyocytes were infected with coxsackievirus at multiplicity of infection (MOI) of 5 for 8 hours. Cells were treated with and without interferon beta 1 in order to determine if treatment activates antiviral response genes and/or viral clearance pathways. 4 total samples (2 for each condition) were analyzed
Project description:Analysis of the microRNA profile exression in hiPSC-CMs. Results provide important information of the miRNAs expressed in hiPSC-CMs under control conditions.
Project description:We describe a combination of methods to induce a more mature phenotype in hiPSC-CMs. RNA-seq analysis was performed to compare gene expression between hiPSC-CMs cultured under standard conditions (GLUC) and those cultured under semi optimized (MM) and fully optimized (MPAT) conditions
Project description:Mitochondria play a crucial role in the differentiation and maturation of human cardiomyocytes (CMs). To identify mitochondrial pathways and regulators that are involved in cardiac differentiation and maturation, we examined human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Proteomic analysis was performed on enriched mitochondrial protein extracts isolated from hiPSC-CMs differentiated from dermal fibroblasts (dFCM) and cardiac fibroblasts (cFCM), at different days of differentiation (between 12 and 115 days), and also from adult and neonatal mouse hearts for comparison. Mitochondrial proteins with a ≥2-fold change between differentiation time points in dFCMs and cFCMs, and between adult versus neonatal mouse hearts, were subjected to Ingenuity Pathway Analysis (IPA), and some upregulated proteins were validated by immunoblotting. The highest significant upregulation was in metabolic pathways for fatty acid oxidation (FAO), the tricarboxylic acid (TCA) cycle, oxidative phosphorylation (OXPHOS) and branched chain amino acid (BCAA) catabolism. The top upstream regulators predicted by IPA were- peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1-a), the insulin receptor and the retinoblastoma protein (Rb) transcriptional repressor. In addition, IPA and immunoblotting showed substantial upregulation of the mitochondrial LonP1 protease, which regulates mitochondrial proteostasis, energetics and metabolism. Using this proteomics approach, we have identified key metabolic and intracellular signaling pathways that are up- and down- regulated during the biogenesis of mitochondria in differentiating and maturing cardiac myocytes.
Project description:Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) are commonly used to model arrhythmogenic cardiomyopathy (ACM), a heritable cardiac disease characterized by severe ventricular arrhythmias, fibrofatty myocardial replacement and progressive ventricular dysfunction. Although ACM is inherited as an autosomal dominant disease, incomplete penetrance and variable expressivity are extremely common, resulting in different clinical manifestations. Here, we propose hiPSC-CMs as a powerful in vitro model to study incomplete penetrance in ACM. Six hiPSC lines were generated from blood samples of three ACM patients carrying a heterozygous deletion of exon 4 in the PKP2 gene, two asymptomatic (ASY) carriers of the same mutation and one healthy control (CTR), all belonging to the same family. Whole exome sequencing was performed in all family members and hiPSC-CMs were examined by ddPCR, western blot, Wes™ immunoassay system, patch clamp, immunofluorescence and RNASeq. Our results show molecular and functional differences between ACM and ASY hiPSC_x0002_CMs, including a higher amount of mutated PKP2 mRNA, a lower expression of the connexin-43 protein, a lower overall density of sodium current, a higher intracellular lipid accumulation and sarcomere disorganization in ACM compared to ASY hiPSC_x0002_CMs. Differentially expressed genes were also found, supporting a predisposition for a fatty phenotype in ACM hiPSC-CMs. These data indicate that hiPSC-CMs are a suitable model to study incomplete penetrance in ACM.
Project description:Methods: RNA-seq libraries were prepared using the Illumina TruSeq RNA kit and the TrueSeq method was employed for mRNA enrichment. The libraries were quantified and samples were multiplexed in each lane of the flowcell. Cluster generation was performed and then sequenced on the Illumina HiSeq2500 system. Reads were mapped on the Human Genome Reference and normalized expression table was generated. Results: RNA-seq results reveal gene expression of cardiac toxicity in hiPSC-CMs that are consistent with alcohol-induced pathophysiology observed in animal models. For example MMP9 is among the top 5 upregulated genes in ethanol-treated hiPSC-CMs, MMP9 concentrations are significantly higher in human sera of chronic alcohol abusers and MMP9 mRNA and protein levels are increased in the myocardium of rats following acute ethanol exposure. Conclusions: Data demonstrate significant alteration in gene expression, among the top 60 genes significantly altered by ethanol exposure, 8 genes are involved in ion channels, which may be in part contributing to the abnormal intracellular Ca2+ transients. Ethanol up-regulated the expression of genes associated with collagen metabolism and extracellular matrix (MMP9, EMID1, COL14A1), most of the downregulated genes are involved in cardiovascular system development (NPPB, DNAAF3), actin filament-based process (LMOD2, MYH4) and muscle contraction (MYL2). These findings are consistent with previous studies showing a correlation between alcohol exposure and defects in heart and circulatory system development.
Project description:Cardiovascular disease is a leading cause of death worldwide. Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) hold immense clinical potential and recent studies have enabled generation of virtually pure hPSC-CMs with high efficiency in chemically defined and xeno-free conditions. Despite these advances, hPSC-CMs exhibit an immature phenotype and are arrhythmogenic in vivo, necessitating development of methods to mature these cells. hPSC-CMs undergo significant metabolic alterations during differentiation and maturation. A detailed analysis of the metabolic changes accompanying maturation of hPSC-CMs may prove useful in identifying new strategies to expedite the maturation process and also provide biomarkers for testing or validating hPSC-CM maturation. In this study we identified global metabolic changes which take place during long-term culture and maturation of hPSC-CMs derived from three different hPSC lines. We have identified several metabolic pathways, including phospholipid metabolism and pantothenate and Coenzyme A metabolism, which showed significant enrichment upon maturation in addition to fatty acid oxidation and metabolism. We also identified an increase in glycerophosphocholine and reduction in phosphocholine as potential metabolic biomarkers of maturation. These biomarkers were also affected in a similar manner during murine heart development in vivo. These results support that hPSC-CM maturation is associated with extensive metabolic rewiring and understanding the role of these metabolic changes in maturation process has the potential to develop novel approaches to monitor and expedite hPSC-CM maturation.
Project description:Drug-induced cardiotoxicity is a widespread clinical issue affecting numerous drug classes and remains difficult to treat. One such drug class is Tyrosine Kinase Inhibitors (TKIs), which cause varying degrees of contraction-related cardiotoxicity usually after weeks of exposure. Understanding molecular mechanisms underlying both acute and chronic toxicity of TKIs could help identify new treatment opportunities. Here, we presented transcriptome responses to four TKIs (Sunitinib, Sorafenib, Lapatinib and Erlotinib) across 3 doses and 4 time points in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Gene expression evolved continually under drug treatment and revealed changes in several biological networks that were associated with cardiac metabolism and contraction. These changes were confirmed by proteomics and resulted in metabolic and structural remodeling of hiPSC-CMs. One of the metabolic remodeling was the increased aerobic glycolysis induced by Sorafenib, which is an adaptive response in preserving cell survival under Sorafenib treatment. Drug adaptation in cardiac cells may represent new targets for managing chronic forms of TKI-induced cardiotoxicity.